Rheology and electrical conductivity of upper mantle: Recent progress and perspectives

Abstract

Melt and heat transfer in the upper mantle play a crucial role in the multi-scale evolution of the lithospheric upper mantle. However, the retention time of large amount of melt in the lithospheric upper mantle is limited, therefore, the estimation of the dynamics process of the melt utilizing rheology and electrical conductivity is the optimal choice in current geophysics. In the past decade, a series of advances have been achieved by researchers with the upgrading of instrumentation and in-depth theoretical simulations. In this review, we summarize the main factors controlling the rheology and electrical conductivity of the upper mantle from a point defect perspective, the physical connection between olivine rheology and electrical conductivity from a point defect perspective, and the inversion for the chemical components of the upper mantle using multiple geophysical data. In addition, the connection of viscosity and electrical conductivity is analyzed in the light of point defects. In the end, further possible directions of research on the rheology and electrical conductivity of the upper mantle are mentioned.